Expendable case shotshell

ABSTRACT

An expendable cartridge made of thermoplastic material which is adapted to contain the necessary propellant, projectile charge, etc., and which is explosively expelled from the gun along with the projectile charge. There are several modifications of the invention, each of which requires some means to slit, fracture, or rupture the outermost cartridge structure, which then permits the inner structure to be released thus facilitating the ultimate final release of the projectile charge from the expendable cartridge, which then falls to the ground much like conventional shot containers.

Kordas et a1,

at fi 19] [541 nxrnnnnnrn CASE snorsrrnu,

[75] Inventors: Martin W. Kordas, Stratford; Robert (I. May, Fairfield; John J.

Scanlon, Monroe, all of Conn.

[73] Assignee: Remington Arms Company, Inc., Bridgeport, Conn.

[22] Filed: Feb. 2, 1971 [21] Appl. No.: 111,949

Related ILS. Application Data [62] Division of Ser. No. 755,649, Aug. 22, 1968.

52 11.s.c1. ..'.....,.102/42-c, 9/14 SB, 102/43 1, 1 102/43 c 51 1m. (:1. .3420 5/30, F42b 7/06 581 Fieid 111 Search .....102 42, 42 c, 43, 43 P, 43 c,

s0 References Cited UNITED STATES PATENTS 3,352,239 11/1967 Schinnerer ..102/42 c 3,577,921 5/1971 Van Langenhoven ..102/38 1451 Apr. 3, 1373 3,427,648 2/1969 Manning et ai l()2/93 FOREIGN PATENTS OR APPLICATIONS 1,449,850 7/1966 France .;l02/42 732,633 6/1955 Great Britain ..102/43 Primary Examiner-Robert F. Stahl Attorney-John H. Lewis, Jr. and Nicholas Skovran [5 7 ABSTRACT An expendable cartridge made of thermoplastic material which is adapted to contain the necessary propellant, projectile charge, etc., and which is explosively expelled from the gun along with the projectile charge. There are several modifications of the invention, each of which requires some means to slit, fracture, or rupture the outermost cartridge structure, which then permits the inner structure to be released thus facilitating the ultimate final release of the projectile chargefrom the expendable cartridge, which then falls to the ground much like conventional shot containers.

26 Qlnims, 14 Drawing Figures PATENTEDAFRI? I915 3,724 376 SHEET 2 [IF 3 =Fic5. 6.

Mavtin W. Kordas JK Robert, C. M8 John J, Sean on Attorneus PATENTED 3 7 sum 3 OF '3 Pie. !2.

FIG. I

\U H 3 5 a MM Q W MK SOW e I WW J H n fi 8 D an a VM M Atwrneu EXPENDABLE CASE SHOTSIIELL This application is a division of Kordas, et all application Ser. No. 755,649, filed Aug. 27, 1968. p

This invention relates to shotshells for firearms and in particular to expendable shotshell bodies designed to be expelled from the muzzle of the firearm along with the shot charge or projectile as a result of theaction of the explosive gases generated by the burning propellant.

In recent years, considerable effort and expense have been expended-particularly by or for the military-to develop so-called caseless ammunition to replace the conventional brass or other metal case cartridges. In addition to the decrease in weight and the decrease in volume, such caseless ammunition is attractive to the military because they do not require metallic cases which must be recovered in the field for re-use (particularly the largerartillery cases). Caseless ammunitially all of the advantages of caseless ammunition and having none of certain of its disadvantages.

Another object of this invention is to provide a cartridg'e having a body which is expelled from the muzzle tion is also cheaper and can have realfunctional advantages. For example, because the entire cartridge is expelled from the gun, the gun system can be simplified over conventional guns which require elaborate extraction and ejection means. For purposes of this discussion, combustible cases, wherein the casing is made of a combustible material, are included with caseless ammunition.

The present invention relatesto another approach which avoids some of the problems encountered with caseless ammunition and which enjoys almost all of the advantages of caseless ammunition.

Caseless ammunition has not been widely accepted to date because of certain disadvantages which have not as vyet been overcome. Thus, caseless cartridges are not waterproof, are structurally weak, and are susceptible to premature of undesirable ignition due to cigarettes, cook-off in a hot gun chamber (especially automatic gun systems), and the like. Solid propellants for such cartridges have a tendency to break up when being handled or loaded, particularly in automatic or autoloading firearms. At present, dimensional control of the propellant is difficult and costly to attain and must be done by grinding or machining.

The present velocities availablein conventional ammunition, i. e., with metal cases, have been limited by the pressure that can be contained safely by existing guns and ammunition cases. In either a caseless or expendable cartridge, the pressure and consequently the velocity is not limited by the strength of a conventional case. It has long been known that firearms can be designed and made which will be able to withstand much higher pressures than presently made and limited by conventional brass cases. The limiting factor then becomes the gas seal which must replace the obturating function now being performed by the metal cases.

The present invention provides an expendable plastic shotshell case or body which is expelled from the muzzle of the firearm along with the shot or other projectile. The plastic body protects the propellant during storage and handling from moisture, unintentional ignition as well as providing structural rigidity. An expendable cartridge made from such a body is only slightly heavier than equivalent caseless ammunition but on the other hand, it avoids or substantially minimizes the problems mentioned above. I

It can be seen that the major object of this invention is to provide an expendable shotshell having substanof a firearm.

Still another object ofthis invention is to provide a cartridge that protects the propellant from its environment during storage and handling but .which leaves no casing'in the firearm chamber to be extracted after firmg.

A further object of this invention is to provide a cartridge that has a case which provides a thermal barrier against accidental ignition and provides sufficient strength for use in automatic or autoloading firearms while leaving no case to be extracted after firing.

Still a further object of this invention is to provide a cartridge with a body that contains propellant and priming means as well as projectile means, which body is expelled through the muzzle of a gun.

An additional object of this invention is to provide an expendable body shotshell having a separate pre-slit shot container and a gun barrel having means therein to strip the body away from the pre-slit shot container, thus facilitating releasing of the projectiles after the shell leaves the muzzle of the firearm.

A still additional object of the invention is to provide an expendable body cartridge having a pre-slit projectile chamber and a frangible body cover designed to rupture or fracture upon firing, thus facilitating release of the projectile after the shell leaves the muzzle of the gun.

Other objects will be apparent from the specification and drawings in which:

FIG. 1 is a sectional side elevation of one form of expendable body for the cartridge which is the subject of this invention shown in position in a firearm chamber;

FIG. 2 is a sectional side elevation of the form of expendable body shotshell loaded with solid propellant which is shown in FIG. I;

FIG. 3 is a sectional side elevation of an expendable body shotshell of the type shown in FIG. 2 loaded with loose or granular propellant held in place by a molded propellant disc;

FIG. 4 is a sectional side elevation of an expendable body shotshell of the type shown in FIG. 2 modified to provide a snap lock groove means at the front end of thebody to secure the shot protector to the body;

FIG. 5 is a sectional side elevation of a portion of an expendable body shotshell showing a snap lock groove. means provided at the rear of the projectile chamber to secure the shot protector to the body;

FIG. 6 is a sectional view of an alternate form of expendable body shotshell shown in position in a shotgun chamber;

FIG. 7 is a sectional side view of an expendable body with the cushioning means integrally formed with the body;

FIG. 8 is a sectional side view of an shotshell wherein the shot containing chamber is closed off by a top wad snapped into place within the body;

FIG. 9 is a sectional side view of a modified expendable body shotshell where the body includes an integral hinged shot containing portion which is retained in place by means of a separate retaining sleeve;

FIG. 9A shows a top view of the cartridge shown in FIG. 9;

expendable body FIG. is a sectional side view of a type of expendable cartridge having a frangible cover member which fits on the outside of the body and over the shot chamber;

FIG. 11 is a sectional side view of a modified design where the transverse wall means is solid and a separate cushioning wad is provided inside the shot chamber;

FIG. 12 shows a modification of the expendable cartridge shown in FIG. 10 in which the transverse wall means is solid; and

FIG. 13'shows another modification of the expendable cartridge in which the body shot protector is eliminated and the frangible cover is the sole shot container in this modification. I

Referring now to the drawings, FIG. 1 illustrates one form of an expendable body 10 for a cartridge 12 positioned in an associated gun 14 before firing. It should be understood that although the drawing shows the invention incorporated in a shotshell, it is intended that the invention applies equally to other conventional projectiles such as so-called rifled slugs and industrial slug loads, etc. For the sake of consistency, all further reference in this specification will be to a shotshell load.

Body 10, and corresponding bodies in modifications described later, can be made by injection molding, cold-forming, or any other conventional method of making plastic articles. Although generally any grade of olefinic polymer or co-polymer can be used, polyethylene is especially suitable for use in the body. Other plastics which are suitable are ABS and ABS alloys (Terpolymer or acrylonitrile, butadiene and styrene), flexible vinyls, polyamides, cellulosics, polycarbonates, and others having suitable impact properties.

Body 10 comprises a tubular member 16 and an imperforate, transverse wall or web member 18, which divides the tubular member 16 into tubular wall portions and 22. (See FIG. 2). Transverse wall 18, together with tubular wall portions 20 and 22, define an openended, forward shot cavity or chamber 24 and an openended, rear propellant cavity or chamber 26, respectively. Wall member 18 must be substantially imperforate in order to insure that the full thrust of the explosive gases, generated in the propellant chamber after ignition or propellant 28, is directed to propel the body 10 through the gun barrel 30.- The explosive gases cannot be permitted to enter the shot chamber 20 where it might melt the shot pellets or affect their trajectories. The intersection of web 18 and tubular wall portion 22 is formed as a radius 32 to avoid a stress riser that would cause the web to be blown or sheared out on fir- Propellant means 28 for the present invention can be either a molded one-piece solid propellant, loose or granular propellant, liquid, or gelled. FIGS. 1 and 2 show the use of a one-piece molded solid propellant 28 in which a recess (not numbered) is formed in which a primer cup 34 is positioned and secured by any wellknown means. Primer cup 34 also has a recess (not numbered) in which a primer 36 (either loose or molded) is secured. Primer cup 34 is made of solid propellant which may or may not be the same propellant as the main propellant charge 28depending on the desired ballistics. The main propellant charge 28 is held in propellant chamber 26 by an interference fit, by

an adhesive, or by any other conventional means. Primer cup 34 and primer 36 can be similarly secured to the main propellant charge. Obviously, the primer cup can be eliminated and the primer inserted directly in a pocket formed in the main propellant charge .(See FIG. 7).

Primer 36 is covered by foiling paper (not shown) or other suitable means and the propellant-primer assembly issealed by a thin film of suitable plastic 38 which can either be fastened with an adhesive or heatsealed to body It). Alternately, coatings such as epoxy, can be used to seal the primer-propellant assembly.

A rim or shoulder 40 is formed on the outside diameter of the body It) to provide a surface for head spacing and support against the firing pin blow. Sufficient restraint is provided to hold the shell back for efficient propellant ignition and burning but restraint is low enough so that the shoulder 40 will release before peak pressure is reached and the entire shell will be expelled from the muzzle.

Although the drawing shows various ways of confining the shot pellets 42 in shot chamber 24, FIGS. 1 and 2 show the use of a shot protector 44 which functions as a shot container as well as the closure means for the cartridge. Shot protector 44 is preferably made of plastic material and includes a tubular side wall portion 46 which is open at its rear end and closed off by a transverse closure wall 418 at the mouth or front end thereof. Slit means 5t) are provided across the closure wall 48 and extending down the tubular side wall to a point adjacent the open end but falling short a predetermined distance to provide an unslit portion 52 which functions as a hinge means, as explained later. A small unslit portion (not shown) may also exist at the center of the front face to secure the multiple sections together at the front, thus holding the shot in place until firing. Shot protector 44 is slidably positioned in the shot chamber 24 and secured therein by any wellknown means, such as an interference fit, which would be the cast in FIGS. I and 2.

The preceding discussion has referred to the modification shown in FIGS. 1 and 2. However, various modifications can be made to this cartridge design within the meaning of the invention.

FIG. 3 shows an expendable cartridge similar to the I one shown in FIG. 2 with some modifications. One change is that the supporting rim or shoulder 40a extends further to the front than the shoulder 40 shown in FIG. 2.

Other ways in which FIG. 3 differs from FIG. 2 are that primer 36 is positioned and secured to a pelletized powder disc 54 which holds loose propellant powder or granules 56 in propellant chamber 245. Groove 58 is formed at the rear end of body It) and extends inwardly into the propellant chamber so that a cooperating rim 540 on disc 54 can be snapped into holding relationship therewith.

FIG. 4 shows a solid molded propellant 28a positioned in the propellant chamber and a primer 36 positioned in a recess (not numbered) in the solid propellant 28a. This figure also shows the use of a groove 60 located at the front end of tubular side wall 46 which cooperates with a corresponding locking rim 62 on the forward end of the shot protector .34 to lock the shot protector within the shot chamber. A forwardly extend- The preceding discussion has related primarily to the expendable cartridge. However, this type of ammuni-' tion requires redesigning of conventional firearms to be able to fire the ammunition. FIG. 1 shows that gun bar-' rel 30 has a longitudinal bore 66 through which the projectiles and the cartridge case are explosively propelled. A gun chamber 68, formed in the rear or breech end of the barrel, has an inwardly projecting abutment 70 which acts as a locating and stop means for shoulder 40 of the expendable cartridge. The position of this abutment 70 locates the cartridge in the gun chamber and provides necessary support to the cartridge so that the primer can be ignited by the firing pin 72 which conventionally moves slidably through the gun bolt 74. A gas seal 76, of the type shown in U.S. Pat. No. 3,166,864, issued on Jan. 26, 1965 to J. J. Scanlon, Jr., is shown in FIG. 1 between the gun bolt and the chamber to prevent the explosive gases from escaping through the rear of the gun barrel and out the receiver. A similar sealing system 72a is also used to seal the firing pin. Obviously, any type of gas seal can be used for the gun bolt and the firing pin.

Located as part of the barrel adjacent the front end of the cartridge when the cartridge is in position in the gun chamber are cutters or lands 78. These cutters 78 can be full length or short and are designed to be impacted by the explosively projected cartridge. The cutters function to cut or fracture the tubular wall portion 20 of the shell body in a plurality of places. Once cut the shell body opens up or peels back after being explosively expelled from the gun barrel much like conventional shot containers. The shot protector 44 and the enclosed shot are thus freed from the body so that the shot protectorcan openup like a clam (because of the slit means 50 and hinge means 52) to permit the shot pellets to proceed towards the target without interruption.

The clam closure can be molded to provide built-in stress to assist opening. As molded, the part would be in a partially open position. -On loading the part would be forced to a closed position thereby causing stress in the part that will cause it to open when restraint is removed.

It is preferable to locate the cutters 78 near the gun chamber or the origin of the bore where the velocity is minimum since it is known that sabot cutters placed near the muzzle are damaged by the high velocities.

An alternative version of the expendable cartridge discussed above is shown in FIG. 6. This modification shows a plastic body 100 with transverse wall or web 118 separating the body into a shot chamber 124 and a propellant chamber 126. integrally formed with the body 100 and extending radially is a ring seal 140 located adjacent web 118, which forms an obturating seal and is positioned in a circumferential recess 18th of gun bolt 174 and clamped against chamber abutment 170. Upon firing, the ring 140 is sheared off body 106 and remains in the gun after the rest of the cartridge is expelled from the gun barrel. The obvious drawback of this modification is that the sheared-off ring Mil must be extracted and ejected from the gun. This modification does give good predetermined restraint force based on the shear strength of the plastic.

The expendable case shot shell shown in FIG. 6 can be made to function so that the rim M0 and the body remain intact during firing and completely exit the bore. This can be done by providing some clearance between the rim Ml) and the chamber so that the rim is not clamped and providing a chamfer at the front of the rim so that the rim will be forced down instead of being sheared off.

FIG. 7 shows an expendable cartridge similar to the one shown in FIG. 2 except that the body 200 has transverse wall or web 218 including an integrally formed cushioning section 282. Obviously, the cushioning section can be made in a variety of designs and can be lengthened or shortened depending on the load of pellets and/or propellant desired.

FIG. 8 shows another modification wherein a body 3W) has a transverse web 318 which with the body defines shot chamber 324 and propellant chamber 326. The propellant and priming means are similar to the modification shown in FIG. 3. Differing from FIG. 3 is the method of closing off the shot chamber and containing the shot charge 342 therein. Tubular wall 320 of body 399 includes a circumferential groove 384 in which a top wad 3%6 is snapped in place. Top wad 386 is preferably made of some frangible material which will disintegrate upon firing so as to avoid obstructing the flight of the shot charge. It can be appreciated that a shot container can be utilized with this modification. Either a shot cup or combination shot containerwad column can be inserted within the shot chamber 324.

FIG. 9 shows a further modification of an expendable cartridge. This modification shows a one-piece plastic body 4WD having an integral web 418 which, with body 4MB, defines shot chamber 324 and a propellant chamber 426. Shot chamber 424 is defined in this modification by transverse web 41%, tubular side wall portion 424 and an integrally formed transverse closure wall member 3%. As can be seen in FIG. 9A, the closure wall 438 has a plurality of transverse slits 49th which extend longitudinally down the tubular side wall 420 as slits 490a and then circumferentially at the lower end of the shot chamber as slits 4190b. This arrangement of slits is effected by molding a plurality of segments (any number can be made two, four, etc.), like flower petals, so that when closed, they form a cylinder closed at the front. The unslit portions 492 actually hold the segments to the transverse web llh and are the link which makes the tubular side wall 42% integral with the rest of the body. In loading the cartridge, the shot charge is placed in the end formed by the segments with the segments spread to form a conical shape. The segments are drawn closed to form a cylinder which encloses the shot and a plastic sleeve 494 is slipped over the segmented wall portions to retain the shape and complete the shell assembly. On firing, sleeve 49 will be cut by the body cutter or land 78 (FIG. 1) to remove the restraint effected by the sleeve so as to permit the release of the shot in flight from the muzzle. Alternatley, sleeve 494 may be of a frangible plastic, and removed from the body by the shock of firing.

As with the other modifications, cushioning means can be provided by molding a collapsible section in the shell body similar to conventional shotshell wads or by inserting a separate cushioning material, such as felt, cork, or plastic foam within the shot chamber under or to the rear of the shot charge. (See reference numeral 599 in FIG. 11).

A different design principle is illustrated in FIG. 10, i. e., shot release by shattering or complete breakup of a portion or all of the shot containing part of the shell by the shock of firing and/or forces exerted by an abutment or by a constriction in the gun bore.

FIG. 10 shows a gun barrel 530 having a longitudinal bore 566 with a first chamber abutment .570 which functions in the same manner as abutment 70 in FIG. 1. Second abutment 596 is located in the gun bore adjacent to the front end of expendable cartridge 500, which is shown in position for firing in FIG. 10.

Cartridge 500 includes a molded plastic body 510 having an integrally formed transverse wall means 518 which, with body 510, defines a shot chamber 524 and polysulfone, and thermosetting plastics such as phenolics, melamines, ureas, alkyds, polyesters, allylics, etc.

Shoulder 540 constitutes a special feature of the design. In addition to the restraint feature, i. e., holding the shell in the chamber after firing until sufficient pressure is built up, etc., the shoulder also serves as an obturator gas check and a means to clean the bore. This part of the shell, i. e., the shoulder 540, is made of polyethylene or some non-frangible material. Because it remains intact during firing and it is larger than the bore, it will sweep the bore clean of particles left by the frangible part of the shell and any powder residue from preceding shots.

FIG. 11 shows a modified expendable cartridge of the type shown in FIG. 10. This modification shows a solid transverse wall 518a and a separate cushioning a propellant chamber 526. Wall means 518 includes a cushioning section 582 integrally formed therewith similar to the showing in FIG. 3.

The propellant chamber 526 etc., are similar to the showing in FIG. 3 and need not be repeated here. There are differences, however, in the shot chamber and closure thereof.

Shot chamber 524 is defined at its rear by the transverse wall means 518 and at its sides by tubular body side wall portion 520 which is integrally formed with the wall means 518. A plurality of slits 590 in side wall 520 extend longitudinally to the mouth end thereof to form a plurality of wall segments much like conventional shot containers in use today which are adapted to pull back and release the shot pellets enclosed therein after being expelled from the muzzle of the gun. Closing off the open end of the tubular side wall portion 520 is a frangible cup-shaped cover 598 which fits over the segmented side wall 520 to hold it in shape and retain the shot therein. The rear end of the cover 598 is secured in some manner, e. g., an interlocking groove (not shown) in the forward face of transverse wall 518. Obviously, other methods of attaching the cover 598 to the body 510 can be utilized.

Upon firing, the cartridge 500 reacts in the same manner as previously explained. When sufficient pressure has built up (almost instantaneously), the shoulder 540 will release and the entire cartridge will move forward in the gun chamber. When the forward end of the explosively propelled cartridge impacts at relatively low velocity against abutment 596-or at a greater velocity against a conventional gun choke, the frangible cover 598 will break up whereupon the segmented side wall portion 520 will be free to open up upon being expelled from the muzzle.

Although abutment 596 is shown adjacent the chamber, it should be appreciated that the abutment may be located anywhere down the gun bore. Also, a tapered bore restriction (not shown) may also be successfully employed.

Cover 598 is made of a frangible plastic which will provide adequate strength for handling but which will break up upon firing. Among materials which would be suitable are polystyrene, rigid vinyls, polyamides, cellulosics, acrylics, chlorinated polyether, phenoxy,

wad 599 positioned under the shot charge 542 and within the shot chamber 524.

FIG. 12 shows the loaded expendable cartridge shown in FIG. 10 but without the gun details and without the integral cushioning section in the transverse wall means.

FIG. 13 shows a modified expendable cartridge similar in some respects to that shown in FIG. 10 except that the tubular side wall portion 520 is omitted. The frangible cover 598 is the sole shot container in this modification. Obviously, this design loses some of the shot protecting and gun bore protecting advantages found in shot containers since the frangible cover will break up upon firing so that there will be little or no plastic between the shot charge 542 and the gun bore during the time the shot is travelling through the gun bore.

What is claimed is:

1. An expendable cartridge adapted to be expelled from the barrel of a gun having inwardly projecting means positioned in said barrel adjacent the front end of the expendable cartridge prior to firing against which the cartridge impacts at relatively low velocity, said expendable cartridge comprising a tubular body member made of thermoplastic material, a transverse wall means integrally formed with said body member to form a forward cavity and a rear cavity therewith, a shot charge positioned in said forward cavity, propellant means and means to ignite the propellant means positioned in said rear cavity, closure means at the forward end of the body member closing off the forward shot-containing cavity to retain the shot charge therein, shoulder means projecting outwardly from the outer surface of said body member adapted to locate and support the cartridge in the gun, said cartridge upon firing being adapted to be explosively propelled against the inwardly projecting means in the gun barrel to rupture at least a portion of said cartridge so that said mouth closure means is free to be released from said forward cavity and to permit the projectiles to leave the cartridge without any interference after the body member and shot charge therein have been explosively expelled from the gun barrel.

2. An expendable cartridge as recited in claim ll wherein said closure means comprises a separate closure member secured to the inside of said tubular body member to close off the forward cavity and retain the shot charge therein, said cartridge being adapted, upon being fired, to be explosively impacted against the inwardly projecting means in the gun barrel to cut the forward tubular portion of the body member to free the closure member whereupon being expelled from the gun barrel, the closure member is released from the shot charge.

3. An expendable cartridge as recited in claim 2 wherein said closure member comprises a cup-shaped shot container having a tubular portion and a transverse end portion, said shot container. being slidably positioned within said forward cavity and having its closed transverse end positioned at the front of the cartridge acting to close off the forward end positioned at the front of the cartridge acting to close off the forward cavity and to retain the shot charge therein, and slit means on said shot container adapted to open up the container upon being released from the body member and being expelled from the gun to cause the shot container to fall away from the shot charge.

4. An expendable cartridge as recited in claim 2 wherein interlocking rim and groove means are provided on the closure member and the body member to provide a positive means securing the closure member to said body member.

5. An expendable cartridge as recited in claim 1 wherein a cushioning means is integrally formed in said transverse wall means.

6. An expendable cartridge as recited in claim 1 wherein said propellant means comprises a main charge of a loose propellant, a molded solid propellant unit secured to said body member and confining the loose propellant within the propellant cavity, and a priming means secured to a recess in said solid propellant unit.

7. An expendable cartridge as recited in claim 1 wherein said propellant means comprises a molded solid main propellant unit positioned in said rear cavity, a recess in said molded main propellant unit, a molded primer cup secured within said recess, and a primer means secured within said primer cup.

8. An expendable cartridge as recited in claim 1 wherein said propellant means is in a non rigid form.

9. An expendable cartridge as recited in claim 1 in which a separate cushion wad is inserted in said forward cavity between the transverse wall means and the shot charge.

10. An expendable cartridge as recited in claim 1 wherein said closure means is integrallyformed with said body member, said closure means comprising a plurality of wall segments separated from each other by slit means, each of said segments being hinged to said body member, and a separate tubular retaining sleeve slidably positioned and secured over a portion of said closure means.

11. An expendable cartridge as recited in claim 1 wherein said closure means comprises a member made of a frangible material which has sufficient strength to close off the forward cavity during handling but which will break up upon firing of the cartridge.

12. An expendable cartridge as recited in claim 1 wherein said closure means comprises a cup-shaped member made of frangible material positioned and secured on the outsideof said body member so as to encircle said forward cavity, said frangible member adapted to be impacted against said inwardly projecting means of the gun and break up so as to free the body member from said closure means.

ill

13. An expendable cartridge as recited in claim 12 wherein said forward cavity is defined by a tubular side wall portion of said body member and said transverse wall means, and slit means in said tubular side wall portion thus forming a plurality of wall segments, each of which is hingedly attached to the body member.

14. In a firearm having a gun bolt with a circumferential recess and a gun barrel having a transverse abutment adjacent to the front end of said gun bolt, an

expendable shotshell cartridge comprising a thermoplastic tubular body member having a first chamber open at one end, propellant means and means to ignite said propellant means positioned and secured within said first chamber, a second chamber at the opposite end of said body member from the first chamber, a shot charge positioned in said second chamber, said first and second chambers being separated from each other by a transverse wall means which prevents the explosive gases formed in the first chamber upon firing from entering into the second chamber, a ring seal means integral with and projecting radially from the outer surface of the body member adjacent said transverse wall means-to act as a support for the cartridge in the gun chamber and also to form an obturating seal upon firing of the cartridge, said ring means being positioned in said circumferential recess and being clamped against said transverse gun barrel abutment so as to be sheared off from said body member upon firing so that the remaining portion of the cartridge is explosively expelled from the gun barrel, leaving only the sheared-off ring means in the barrel to be extracted.

15. An expendable ammunition cartridge adapted to be expelled from the barrel of a gun having a slitter means positioned in the gun barrel, said expendable cartridge comprising a body member made of thermoplastic material, a transverse wall means integrally formed with said body member to define therewith a propellant chamber at the rear thereof and a projectile chamber at the front thereof, a plurality of projectiles positioned in said projectile chamber, propellant means and priming means positioned in said propellant chamber, said projectile chamber including tubular side wall means and a front transverse closure wall integrally formed with said body member, slit means in said side wall means and said closure wall to hinge said side wall means and said closure wall to said body member, an outer retaining sleeve of thermoplastic material slidably positioned over said hinged side wall means to support the side wall means until after firing whereupon said outer retaining sleeve engages the slitter in thegun barrel to cut off and thus permit the side wall means to hinge and fall away from the enclosed projectiles.

16. An expendable ammunition cartridge adapted to be expelled from the barrel of a gun, said expendable cartridge comprising a body member made of thermoplastic material, a transverse wall means integrally formed with said body member to define therewith a propellant chamber at the rear thereof and a projectile chamber at the front thereof, a plurality of projectiles positioned in said projectile chamber, propellant means and priming means positioned in said propellant chamber, said projectile chamber including tubular side wall means and a front transverse closure wall integrally formed with said body member, slit means in said side wall means and said closure wall to hinge said side wall means and said closure wall to said body member, an outer retaining sleeve of a frangible plastic material slidably positioned over said side wall means to support the side wall means until after firing whereupon said outer retaining sleeve is adapted to break up and thus permit the side wall means to hinge and fall away from the enclosed projectiles.

17. In combination with a gun barrel having a longitudinal bore therethrough for the passage of one or more projectiles, a chamber at the breech end of the barrel, support means in said chamber to locate and support a cartridge therein prior to firing; and expendable cartridge comprising a body member having a first open-ended cavity having a propellant'means and priming means positioned and secured therein, a second open-ended projectile cavity having a plurality of projectiles positioned therein, means extending radially from the outer surface of said body member to cooperate with said support means in the gun chamber to locate and support the cartridge in the gun chamber, means closing off the open end of said projectile cavity and retaining the projectiles therein, and inwardly projecting means in the gun bore positioned adjacent the front end of the cartridge before firing, said cartridge adapted to be explosively projected through the gun bore until the cartridge impacts the inwardly projecting means of the gun barrel at a relatively low velocity whereupon at least a portion of the cartridge is ruptured to facilitate the opening up of the projectile cavity after leaving the muzzle of the gun in order to be released from the projectiles.

18. The combination recited in claim 17 wherein said means closing off the open end of said projectile cavity comprises a separate combination shot protector-closure member slidably positioned in said open-ended projectile cavity, slit means designed to open up said protector-closure member and release said shot charge after the protector-closure member is first released from the body member subsequent to slitting of said body member upon being explosively impacted against the inwardly projecting means of the gun barrel.

19. The combination recited in claim 18 wherein interlocking means are provided on said body member and said protector-closure member to lock the two members together and hold the protector-closure member in said projectile cavity prior to firing.

20. The combination recited in claim 17 wherein said projectile cavity is defined by a transverse wall means located intermediate the two ends of the body member and a plurality of segmented tubular side wall portions of said body member, said means closing off the open end of said projectile cavity comprising a separate frangible cup-shaped member attached to said body member and which functions to retain said segmented side wall portions in shot containing position and to close off the open end of the projectile cavity, said frangible member adapted to break-up upon being explosively impacted against the inwardly projecting means of the gun barrel thus freeing the segmented side wall portions from restraint upon being expelled from the muzzle of the gun.

21. The combination recited in claim 17 wherein the body member and the separate closure means are made of afol olefinicmaterial. I

2 e combination recited in claim 17 wherein the body member is made of a polyolefinic material and the closure means is made of a polystyrene.

23. The combination recited in claim 17 wherein the body member is made of polycarbonate plastic material.

24. The combination recited in claim 17 wherein the body member is made of a plastic material having an impact strength of over about one foot per inch of notch as measured by a standard notched Izod test.

25. A firing system wherein the cartridge casing which encloses the propellant and projectiles is expelled from the gun barrel along with the projectiles, which casing then is stripped from the projectiles after leaving the muzzle of the gun to fall to the ground while the projectiles go ahead to the target, said system comprising a gun having a gun chamber with means to locate and to support the associated cartridge during firing, an expendable cartridge having a body member with a front tubular portion in which a plurality of projectiles are positioned, a rear tubular portion in which propellant means and priming means are positioned and secured, a transverse wall means separating said front and rear tubular portions, means projecting radially from the outer surface of one of said tubular portions to cooperate with the corresponding means in the gun chamber to locate and support the cartridge in the gun chamber, a closure means on said front tubular portion of the cartridge to close off the open end of said front tubular portion and to retain the projectiles therein, and means located in the gun barrel adjacent the front end of said cartridge before firing adapted to interrupt the cartridge while the cartridge is being propelled through the gun barrel at a relatively low velocity to fracture at least a part of the cartridge to facilitate opening up of the cartridge after leaving the muzzle of the gun so that the projectiles are released without affecting their trajectories.

26. An expendable cartridge adapted to be expelled from the barrel of a gun having inwardly projecting means positioned in said barrel adjacent the front end of the expendable cartridge prior to firing against which the cartridge impacts upon firing, said expendable cartridge comprising a tubular body member made of thermoplastic material, said body member having a first chamber, propellant means and priming means positioned and retained in said first chamber, a second chamber at the opposite end of the body member, projectile means in said second chamber, said first and second chambers being separated from each other by a transverse sealing wall, and shoulder means projecting outwardly from the outer surface of said body member for locating and supporting the cartridge in the gun before firing but permitting release of the cartridge from the gun upon firing so that essentially the entire cartridge is expelled from the gun barrel; at least a portion of the cartridge being ruptured by said inwardly projecting means in the gun barrel in order to permit the projectile means to separate from the body member after leaving the muzzle of the gun.

gggg UNITED STATES PATENT OFFICE I CERTIFICATE OF CQRRECTION Patent no, 3,724,376 Dated April 3 1973 A Invehtofl s) MARTIN W. KORDAS, ROBERT C. MAY, and JOHN J. SCANLON- It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 1, Line 36, "of" should read as --or Col. 3, Line 47,

"or" should read as ---of Signed end sealed this. 11th day, of June 19714.,

(SEAL) Attest:

EDWARD MJLETCKER R. f c. MARSHALL 1mm, Atteating Officer I Comissioner of Patents Pv-ww UNITED STATES PATENT OFFICE 569 CERTIFICATE OF CORRECTION I Patent No- 3,72 1 '3 76 mated April 3, 1973 Inveritox-(s) MARTIN w. KORDAS, ROBERT c. MAY, and JOHN J. SCANLON It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 1, Line 36, of" should read as -or--} Col. 3, Line 47, "or" should read as of Signed and sealed this 11th day of June 197 (SEAL) Attest:

EDWARD M.FLETCHER,JR. cymnsmmmun Attesting Officer Commissioner of Patents 

1. An expendable cartridge adapted to be expelled from the barrel of a gun having inwardly projecting means positioned in said barrel adjacent the front end of the expendable cartridge prior to firing against which the cartridge impacts at relatively low velocity, said expendable cartridge comprising a tubular body member made of thermoplastic material, a transverse wall means integrally formed with said body member to form a forward cavity and a rear cavity therewith, a shot charge positioned in said forward cavity, propellant means and means to ignite the propellant means positioned in said rear cavity, closure means at the forward end of the body member closing off the forward shotcontaining cavity to retain the shot charge therein, shoulder means projecting outwardly from the outer surface of said body member adapted to locate and support the cartridge in the gun, said cartridge upon firing being adapted to be explosively propelled against the inwardly projecting means in the gun barrel to rupture at least a portion of said cartridge so that said mouth closure means is free to be released from said forward cavity and to permit the projectiles to leave the cartridge without any interference after the body member and shot charge therein have been explosively expelled from the gun barrel.
 2. An expendable cartridge as recited in claim 1 wherein said closure means comprises a separate closure member secured to the inside of said tubular body member to close off the forward cavity and retain the shot charge tHerein, said cartridge being adapted, upon being fired, to be explosively impacted against the inwardly projecting means in the gun barrel to cut the forward tubular portion of the body member to free the closure member whereupon being expelled from the gun barrel, the closure member is released from the shot charge.
 3. An expendable cartridge as recited in claim 2 wherein said closure member comprises a cup-shaped shot container having a tubular portion and a transverse end portion, said shot container being slidably positioned within said forward cavity and having its closed transverse end positioned at the front of the cartridge acting to close off the forward end positioned at the front of the cartridge acting to close off the forward cavity and to retain the shot charge therein, and slit means on said shot container adapted to open up the container upon being released from the body member and being expelled from the gun to cause the shot container to fall away from the shot charge.
 4. An expendable cartridge as recited in claim 2 wherein interlocking rim and groove means are provided on the closure member and the body member to provide a positive means securing the closure member to said body member.
 5. An expendable cartridge as recited in claim 1 wherein a cushioning means is integrally formed in said transverse wall means.
 6. An expendable cartridge as recited in claim 1 wherein said propellant means comprises a main charge of a loose propellant, a molded solid propellant unit secured to said body member and confining the loose propellant within the propellant cavity, and a priming means secured to a recess in said solid propellant unit.
 7. An expendable cartridge as recited in claim 1 wherein said propellant means comprises a molded solid main propellant unit positioned in said rear cavity, a recess in said molded main propellant unit, a molded primer cup secured within said recess, and a primer means secured within said primer cup.
 8. An expendable cartridge as recited in claim 1 wherein said propellant means is in a non-rigid form.
 9. An expendable cartridge as recited in claim 1 in which a separate cushion wad is inserted in said forward cavity between the transverse wall means and the shot charge.
 10. An expendable cartridge as recited in claim 1 wherein said closure means is integrally formed with said body member, said closure means comprising a plurality of wall segments separated from each other by slit means, each of said segments being hinged to said body member, and a separate tubular retaining sleeve slidably positioned and secured over a portion of said closure means.
 11. An expendable cartridge as recited in claim 1 wherein said closure means comprises a member made of a frangible material which has sufficient strength to close off the forward cavity during handling but which will break up upon firing of the cartridge.
 12. An expendable cartridge as recited in claim 1 wherein said closure means comprises a cup-shaped member made of frangible material positioned and secured on the outside of said body member so as to encircle said forward cavity, said frangible member adapted to be impacted against said inwardly projecting means of the gun and break up so as to free the body member from said closure means.
 13. An expendable cartridge as recited in claim 12 wherein said forward cavity is defined by a tubular side wall portion of said body member and said transverse wall means, and slit means in said tubular side wall portion thus forming a plurality of wall segments, each of which is hingedly attached to the body member.
 14. In a firearm having a gun bolt with a circumferential recess and a gun barrel having a transverse abutment adjacent to the front end of said gun bolt, an expendable shotshell cartridge comprising a thermoplastic tubular body member having a first chamber open at one end, propellant means and means to ignite said propellant means positioned and secured within said first chamber, a second chamber at The opposite end of said body member from the first chamber, a shot charge positioned in said second chamber, said first and second chambers being separated from each other by a transverse wall means which prevents the explosive gases formed in the first chamber upon firing from entering into the second chamber, a ring seal means integral with and projecting radially from the outer surface of the body member adjacent said transverse wall means to act as a support for the cartridge in the gun chamber and also to form an obturating seal upon firing of the cartridge, said ring means being positioned in said circumferential recess and being clamped against said transverse gun barrel abutment so as to be sheared off from said body member upon firing so that the remaining portion of the cartridge is explosively expelled from the gun barrel, leaving only the sheared-off ring means in the barrel to be extracted.
 15. An expendable ammunition cartridge adapted to be expelled from the barrel of a gun having a slitter means positioned in the gun barrel, said expendable cartridge comprising a body member made of thermoplastic material, a transverse wall means integrally formed with said body member to define therewith a propellant chamber at the rear thereof and a projectile chamber at the front thereof, a plurality of projectiles positioned in said projectile chamber, propellant means and priming means positioned in said propellant chamber, said projectile chamber including tubular side wall means and a front transverse closure wall integrally formed with said body member, slit means in said side wall means and said closure wall to hinge said side wall means and said closure wall to said body member, an outer retaining sleeve of thermoplastic material slidably positioned over said hinged side wall means to support the side wall means until after firing whereupon said outer retaining sleeve engages the slitter in the gun barrel to cut off and thus permit the side wall means to hinge and fall away from the enclosed projectiles.
 16. An expendable ammunition cartridge adapted to be expelled from the barrel of a gun, said expendable cartridge comprising a body member made of thermoplastic material, a transverse wall means integrally formed with said body member to define therewith a propellant chamber at the rear thereof and a projectile chamber at the front thereof, a plurality of projectiles positioned in said projectile chamber, propellant means and priming means positioned in said propellant chamber, said projectile chamber including tubular side wall means and a front transverse closure wall integrally formed with said body member, slit means in said side wall means and said closure wall to hinge said side wall means and said closure wall to said body member, an outer retaining sleeve of a frangible plastic material slidably positioned over said side wall means to support the side wall means until after firing whereupon said outer retaining sleeve is adapted to break up and thus permit the side wall means to hinge and fall away from the enclosed projectiles.
 17. In combination with a gun barrel having a longitudinal bore therethrough for the passage of one or more projectiles, a chamber at the breech end of the barrel, support means in said chamber to locate and support a cartridge therein prior to firing; and expendable cartridge comprising a body member having a first open-ended cavity having a propellant means and priming means positioned and secured therein, a second open-ended projectile cavity having a plurality of projectiles positioned therein, means extending radially from the outer surface of said body member to cooperate with said support means in the gun chamber to locate and support the cartridge in the gun chamber, means closing off the open end of said projectile cavity and retaining the projectiles therein, and inwardly projecting means in the gun bore positioned adjacent the front end of the cartridge before firing, said cartridge adapted to be explosively projEcted through the gun bore until the cartridge impacts the inwardly projecting means of the gun barrel at a relatively low velocity whereupon at least a portion of the cartridge is ruptured to facilitate the opening up of the projectile cavity after leaving the muzzle of the gun in order to be released from the projectiles.
 18. The combination recited in claim 17 wherein said means closing off the open end of said projectile cavity comprises a separate combination shot protector-closure member slidably positioned in said open-ended projectile cavity, slit means designed to open up said protector-closure member and release said shot charge after the protector-closure member is first released from the body member subsequent to slitting of said body member upon being explosively impacted against the inwardly projecting means of the gun barrel.
 19. The combination recited in claim 18 wherein interlocking means are provided on said body member and said protector-closure member to lock the two members together and hold the protector-closure member in said projectile cavity prior to firing.
 20. The combination recited in claim 17 wherein said projectile cavity is defined by a transverse wall means located intermediate the two ends of the body member and a plurality of segmented tubular side wall portions of said body member, said means closing off the open end of said projectile cavity comprising a separate frangible cup-shaped member attached to said body member and which functions to retain said segmented side wall portions in shot containing position and to close off the open end of the projectile cavity, said frangible member adapted to break-up upon being explosively impacted against the inwardly projecting means of the gun barrel thus freeing the segmented side wall portions from restraint upon being expelled from the muzzle of the gun.
 21. The combination recited in claim 17 wherein the body member and the separate closure means are made of a polyolefinic material.
 22. The combination recited in claim 17 wherein the body member is made of a polyolefinic material and the closure means is made of a polystyrene.
 23. The combination recited in claim 17 wherein the body member is made of polycarbonate plastic material.
 24. The combination recited in claim 17 wherein the body member is made of a plastic material having an impact strength of over about one foot per inch of notch as measured by a standard notched Izod test.
 25. A firing system wherein the cartridge casing which encloses the propellant and projectiles is expelled from the gun barrel along with the projectiles, which casing then is stripped from the projectiles after leaving the muzzle of the gun to fall to the ground while the projectiles go ahead to the target, said system comprising a gun having a gun chamber with means to locate and to support the associated cartridge during firing, an expendable cartridge having a body member with a front tubular portion in which a plurality of projectiles are positioned, a rear tubular portion in which propellant means and priming means are positioned and secured, a transverse wall means separating said front and rear tubular portions, means projecting radially from the outer surface of one of said tubular portions to cooperate with the corresponding means in the gun chamber to locate and support the cartridge in the gun chamber, a closure means on said front tubular portion of the cartridge to close off the open end of said front tubular portion and to retain the projectiles therein, and means located in the gun barrel adjacent the front end of said cartridge before firing adapted to interrupt the cartridge while the cartridge is being propelled through the gun barrel at a relatively low velocity to fracture at least a part of the cartridge to facilitate opening up of the cartridge after leaving the muzzle of the gun so that the projectiles are released without affecting their trajectories.
 26. An expendable cartridge adapted to be expelled from the barrEl of a gun having inwardly projecting means positioned in said barrel adjacent the front end of the expendable cartridge prior to firing against which the cartridge impacts upon firing, said expendable cartridge comprising a tubular body member made of thermoplastic material, said body member having a first chamber, propellant means and priming means positioned and retained in said first chamber, a second chamber at the opposite end of the body member, projectile means in said second chamber, said first and second chambers being separated from each other by a transverse sealing wall, and shoulder means projecting outwardly from the outer surface of said body member for locating and supporting the cartridge in the gun before firing but permitting release of the cartridge from the gun upon firing so that essentially the entire cartridge is expelled from the gun barrel; at least a portion of the cartridge being ruptured by said inwardly projecting means in the gun barrel in order to permit the projectile means to separate from the body member after leaving the muzzle of the gun. 